This invention relates to a windshield wiper for automobiles, and more particularly to an improvement in the mechanism of detachably coupling the wiper arm and the wiper blade using a leaf spring suitably shaped and held in the wiper blade.
In windshield wipers for automobiles, the wiper blade must be detachable from the wiper arm for the purpose of replacement. Customarily a clip is placed on and connected to the primary lever of a wiper blade assembly, and the wiper blade can be detachably coupled with the wiper arm by inserting the wiper arm tip into the clip.
Currently, some automobile windshield wipers are using a different method of coupling the wiper blade with the wiper arm. That is, a spring called a support spring, which is formed by bending a leaf spring so as to have a nearly U-shaped end portion, is held in the primary lever of the wiper blade. The support spring hooks over a retainer pin. The primary lever has an opening which provides access to the support spring. The tip portion of the wiper arm is bent in conformity with the U-shaped portion of the support spring. The bent tip portion of the wiper arm is inserted into the primary lever of the wiper blade to fit on the U-shaped portion of the support spring. When detaching the wiper blade from the wiper arm, a fingertip is inserted into the interior of the primary lever by using a space between the primary lever and the packing on the blade rubber in order to press a free end of the support spring to thereby release the tip portion of the wiper arm from the force of the support spring.
This coupling mechanism is simple in construction, but there is some doubt as to the sureness or stableness of the coupling since the coupling is made merely by the frictional contact of the U-shaped tip portion of the wiper arm with the similarly shaped support spring. Besides, the manipulation of the support spring in detaching the wiper blade from the wiper arm is troublesome because of the need of inserting the fingertip into the narrow space within the primary lever to touch the free end of the support spring. If this coupling mechanism is employed in a windshield wiper unit of the so-called hidden or concealed type, the fingertip must be inserted into the primary lever with much difficulty because the wiper blade cannot be kept apart from the windshield by raising the wiper arm.